1. Field of the Invention
The present invention relates to chest drainage systems for draining gas and exudate from a patient following surgery.
2. Description of the Related Art
Chest drainage systems generally include at least one bottle connected to a patient to collect gas and exudate leaking into the thoracic cavity, by allowing drainage to a position lower than the patient while still allowing the patient to breathe. Depending on the needs of a particular patient, chest drainage systems can be set up to operate in different modes. In one mode, drainage can take place by gravity alone and, in other modes, drainage is assisted by the application of external suction by attaching a suction line to the system. A typical chest drainage system will include one, two, or three series—connected bottles depending on the particular set-up. Irrespective of the actual set-up used, one of the bottles will usually include a water seal associated with the inlet tube to that bottle to ensure that air or gas cannot return along the tube once it has bubbled out of the tube; thus the water seal acts as a one-way valve ensuring drainage away from the cavity without permitting air to return. Depending on the set-up used, the system may also have a separate collection bottle and a bottle for controlling the degree of suction.
However, a life-threatening situation can occur if the outlet to one or more of the bottles is closed, for example by being blocked or pinched off whereby the drainage action is restricted with the result that eventually the patient may no longer be able to breathe. This situation is known as pneumothorax. Blockage of an outlet can occur if an outlet tube or  suction tube becomes kinked or if a valve linking a suction tube to a suction system is closed without the line being disconnected from the valve.